Abstract:

To solve the problems of insensitive response and low degree photoresponse in wide bandgap semiconductor UV(ultraviolet)  photodetectors,Pt electrodes with high work function was introduced to TiO₂ ultraviolet detectors. TiO₂ ultraviolet detectors with Pt electrodes have been fabricated and studied. Nano TiO₂ thin films were prepared by sol- gel method,and Pt film was deposited by radio frequency magnetron sputtering directly on the semiconductor films. At 5 V bias,the dark current of the detectors was 4.5 nA,and the photocurrent was 5.7 μA under irradiation of 260 nm UV light. High photoresponse of 447 A/W was found under irradiation of 260 nm UV light,which is much higher than those of photodetectors with other electrodes (about 200 A/W).At last,the peripheral circuit was designed and the final UV photodetector was fabricated. Experiments show that the detector successfully solve the problems of traditional wide-bandgap semiconductor ultraviolet detector.

Key words: ultraviolet , detector, nano TiO₂, metal-semiconductor-metal(MSM)